Why are some Sonos products found as Airplay devices and some as RAAT devices by Roon?
Please excuse me for having to correct you, but Sonos devices do not have an implemented RAAT, instead roon uses the Sonos protocol.
Consequently, you can not group Sonos devices with RAAT, but only Sonos devices with each other.
I have a Sonos One, which can be addressed both under the Sonos protocol, as well as by airplay. Both “devices” have the same IP address.
Newer Sonos devices with implemented airplay should appear twice each time and not either or.